Automatic impulse coupling for magnetos



L F. BURGER Feb. 24, 1931.

AUTOMATIC IMPULSE COUPLING FOR MAGNETOS Filed May 19, 1928 4 Sheets-Sheet 1 hm w , ivewr Jag @Zdfiarger Feb. 24, 1931.

L. F. BURGER AUTOMATIC IMPULSE COUPLING FOR MAGNETOS Filed May 19, 1928 4 Sheets$heet 2 Feb. 24, 1931.

L. F. BURGER AUTOMATIC IMPULISE COUPLING FOR MAGNETOS Filed May 19, 1928 4 Sheets-Sheet 3 Feb. 24, 1931. BURGER 1,793,586

AUTOMATIC IMPULISE COUPLING FOR MAGNETOS Filed May 19, 1928 4 Sheets-Sheet 4 11 22062230) Jegzaalflfiwye/ I fi W/am J LHy Patented Feb. 24, 1931 I NETED STATES PATENT ()FFHCE LEOPOLD F. BURGER, OF RIVERSIDE, ILLINOIS, ASSIGNOR TO INTERNATIOJAL HARVESTER COMFANY, A CORPORATION OF NEW JERSEY AUTOMATIC IMPULSE COUPLING FOR MAGNETOS Application filed May 19, 1928. Serial No. 2%,968.

This invention relates to improvements in breakage, due to the great shocks to which a driving device for magneto generators. this part is necessarily subjected. Objec- Such devices are commonly designated as tionable noise is also an incident to this hamimpulse couplings or starters. mering action when the driven part stops.

5 As is well known in the art, the magneto Most couplings, furthermore,have their parts which supplies the electrical spark for the exposed to dust and dirt, which causes wear. ignition devices of an internal combustion lVith thisintroductory statement'in'mind, engine is driven from the engine, nd, as it is the main object of the'invention generala result, when the engine is turning over ly to improve the construction and operation slowly, as when starting, necessarily the magof impulse couplings of the kind mentioned. 6 neto also must be turning over slowly, and, lilo-re particular objects are to provide a as a result, the magneto at such times cannovel form of buffer or shock absorbingmeans not deliver that necessary hot spark required interposed between the driving and driven for ignition purposes within the engine. Imparts in such a manner that the severe shocks pulse couplings, therefore, are used between to which the driven parts are subjected will 05 the engine and magneto drive to'correct this e materially lessened with a resultant great deficiency by turning over the magneto armaer longevity for the coupling parts; to lessen ture, when the engine is running slowly, the noise of 01 oration; to enclose the parts momentarily at a greater speed than the in dirt proof casing; to minimize the wear 120 engine, such momentary magneto acceleraon parts; and, lastly, to provide a coupling tion being timed to take place at the moment having a maximum number of sheet metal the respective pistons of the engine are on parts which can be easily worked and matheir compression strokes because that is chined to the end that the coupling may be when ignition is effected and thus the magpracticable from a manufacturing viewpoint.

neto can deliver at this time the necessary Other and further objects of this invention 7 hot spark. Impulse couplings, therefore, will be apparent to anyone skilled in this art cause the magneto to supply sparks of high after reading the specification with reference intensity independently of the engine speed, to the accompanying sheets of drawings, such sparks being equal to those delivered by wherein illus rated a practicable embodi- 30 the magneto when the engine is running at ment of the inve ition. In these drawings:

normal speed. Ligure l is a general, vertical sectional Briefly, such couplings comprise a driven view through the assembled impulse couplin part secured to the magneto shaft or rotor, the view showing the coupling associated a driving part conn cted with an accessory with the armature shaft of a magneto. The

135 engine orive shaft and having a resilient showing is twice actual size; member forming a driving connection be- Figure 2 is an inside face view, actual size,

tween the driving and driven parts. A latch of the driving member and the buffer shell, means is used momentarily to stop the driven minus the buffer spring fitted thereinto; part'to hold the magneto shaft stationary for Figure 3 is a face view of the assembled 40 apredetermined period, this stopping of the coupling, with the dust proof cover removed, so driven parts causing the resilient means to as seen along the line 33 of Figure 1, look become energized, due to the driving part ing in the direction of the arrows, the armahaving been driven ahead of the driven part. ture shaft ofthe magneto and an abutment Now, when the latch is released, of course, appearing in section;

'45 the driven part and magneto shaft are im- Figure 4: is a view similar to the showing 9 pelled ahead under the power of the resilient in Figure 3, the parts, however, assuming a means, causing the magneto to generate the somewhat different position;

requisite hot spark. Figure 5 is a side view of the assembled This alternate starting and sudden stopcoupling, with the driving member shown ping of the driven part causes wear and in section to show the relatii e angular posi- .00

tions of the buffer shell and driven part, just prior to the moment the driven part is impulsed ahead;

Figure 6'is a view similar to Figure 5, but showing the position of the parts just as the winding action on the impulsing spring is initiated;

. Figure 7 is an inside face view of the driven part showing the manner of connecting the impulsing spring between the rim of said driven part and the hub of the driving part;

Figure 8 is a view like Figure 2, but addi tionally showing the manner of connecting the buffer spring between the rim of the buffer shell and the hub of the driving part;

Figure 9 is an isolated, rear perspective view of the abutment plate which isto be carried on the magneto frame;

more locking parts;

F gure 19 is an isolated, inside perspective view of the driving part; 7

Figure 20 is an isolated, inside perspective view of the buffer shell; and I Figures 21, 22, 23 and 24 are isolated perspective views, respectively, of a washer; the buffer spring; another washer; and the driving or impulsing spring, all of these parts being shown in the order of their arrangevm'ent when the coupling has been assembled.

Referring now to Figure 1 of the drawings,

1 it will be seen that a portion of a magneto has been shown at 25, the same being conventionally carried on an engine accessory 1 p I p blZLCKGt 20 having a part 26 spaced II'OIH the magneto. The part 26 carries a'shaft 27 driven from any su1table part of the engine, in this'instance the shaft being run in a clockwise direction as viewed from left to right in the drawings. In line with the shaft 2?, the magneto is provided with the usual V armature or magneto shaft 28 havin a tapering, protruding end 29 terminating in a threaded portion 30.

The impulse coupling of which this invention is the subject-matter is interposed between the engine driven shaft 27 and the shaft 28 of the magneto, thepurpose of the coupling, as has been stated, being to cause the magneto shaft to rotate at an intermittently accelerated speed with respect to that of the engine driven shaft when starting the engine from rest.

The magneto has securely mounted on its frame, by means of screw bolts 31, an abutment plate 32, said plate having holes 33, as shown in Figures 1,9 and 10, for the reception of said screw bolts. plate has at its top a centering notch 34c and a each side a notch .35, the side notches designed for the reception of detachable spring clips 36, also shown in Figure 11. This abutment plate in practice will be a sheet 1 stamping having its entire peripheral edge formed with an offset wall or extension 37 extending in the direction of the magneto and snugly fitting thereagainst in a manner to permit the space between the magneto face and the face of the abutment plate to be packed with a fibrous packing, not shown, in a manner best to. exclude dirt and the like.

' The face of this plate is formed with a substrengthening rib 3Y9 protruding from. its bacl; side in the direction of theniagneto;

Arie-upper, top, front face of thisplate is providedatthe top edge of the opening 38 with an integrally formed abutment 40, extending a shortdistance in a direction away from the magneto. The front face of the abutment plate 32 is formed with a circular upset l1, as best shown in Figures 1 and 10. The purpose of the upsetjust described wil later appear. The driven part of the eonpling and its mounting will next be de scribed.

Securely fastened to the tapered part 29 of the magneto armature shaft, by means of a key 42, is the correspondingly tapered por- 'tion of an elongated hub 43 extending away from the magneto a substantial distance, as shown. This hub (see Figures 1, 12 and 13) carries intermediately' of its ends, a circular dish a, which at diametrically opposite points carries rivets a5 extending in the direction of the magneto; each rivet, of which here are two, pivotallv carrying alatch 46.

' See also Figures 3 4, where it can be seen that each latch has a tail 47, .a relatively long, weighted end 48, an inner notch 49 adapted to engage the abutment as will later appear, and a small nib 50. The disk 44, which in practice will be a stamping is formed with a rim 51 directed away from the .magneto, and, at diametrically opposed points, said rim is provided with two extenions 52 as continuations of the rim and each extension of a circumferential or angular length, in this embodiment of the invention, of substantially 41:0 degrees. For convenience of manufacture, the end edges of these exing comprises asheet metal sleeve 81 having an annular beaded pocket 82 at one end designed for the reception 0; packing ring 83 to make a dust proof joint. Tne opposite end of the housing sleeve slips over the oset ll on. the abut -ent plate 3 to prev its displacement. The snap clips 36 securely and detachably hold the cover in place, one l of the clips 36 engaging the notches 05 in the abutment plate and the ot d of the clips engaging the beaded edge 8-, as will he l bling the impulse coupling scribed.

It will be assumed that the abutment plate 32 has been secured to the magneto frame in the manner described and as best shown in Figure 1. The driven part is then secured to the armature shaft of the magneto by means of the key 42 and tie nut The latches 4:603": the driven part are now in a position to engage their notches ll) on the abutment of the abutment plate. The driving part then has the buffer shell fitted thereinto over its hub 5'? in such a niannor that the slot 76 of the shell tits over the extension 60 of the driving part, as shown in Figure2. A washer 84- (see Figures 1 and 21) .is'then-slid overthe hub 5. Next in ordercomes the buffer spring 80 having one end anchored in the slot 7 2 of the hub of the will n eXt drivin cart and its other endanchored in the slot 79 inthe rim of the'buffe'r shell,

Figure'i). This spring is stresscd'hefore 1t abutting the adjacent end of is locked in the shell and-as its ends anchored, the spring 80 is always under pres sure. Thus, the butter spring is far more efficient than if it were not kept under stress, and is not so easily broken. The tendency of the spring being to unwinditself, which it cannot do because of its tired anchors, causes the butter shell to he maintained a position with one end of its slot 76 tightly the radial extension of the driven part '(see Figure 2). This is possible because the buffer shell is to some extent relatively. rotatable with rcspect to the driving part, and because the driven part extension 60 is of shorter angular length than the slot 76.

driving part and buffer is now ready for association with the driven part. A .vasher 85 is now laid against the butter spring {see Figures 1 and 23). Then the driver'or nipelling spring 73 is fitted into the driven part by having one end anchored in the slot 53 of the driven part and theother end anchored in the slot 72 in the hub of the driving part. After this, the driving part with the louder is Itted over the hub e3 the driven part in a manner to cause the e tensions 71 o overhang the latches 46. At the same time the buffer shell extensions l8 dovetail between the extensions 52 of the driven part, as shown inl igures 1, 5 and understood. P19 manner of assemihe assembled The lock ring 6% is then put in place as has been described. When the driving head 68 is coupled with the tongues 67 of the driving part and the parts have been enclosed by the shell 81, the impulse coupling is assembled and ready for operation, which will now be described.

The driving head 68 is being turned in a clockwise direction by the engine and, dueto its positive connection 67 with the driving shell 70, the driving part also turns clock wise. We will assume that the'engine is just starting, its rotative speed being slow, which causes one of the latches as (that one which happens to be uppermost at the time) to gravitate in a manner causing its notch as to lock over the abutment l-O of the abutment plate This starting position of the parts is shown in Figure 3. In the meantime it will be remembered that the buffer spring 80, which is always under stress, tends to unwind itself, but, due to its lined anchors, it cannot do this. However, the net result of this unwinding tendency is to cause the butter shell to rotate slightly, relatively to the driving part, in such a manner that the left hand end of the slot 76, as seen in Figure 2, is held tightly against the left hand end of the radial driving extension 60 of the driving dish part 59, movable as a unit with toe driving part 61. This means that, as the said driving part'rotates, 1t (32111 188 with it the buffer shell Z4; As the louder spring 80 is 5. Justbefore the end of the extension 78 of thebun er rim "Z7 is about to contact the achacent edge of the extension 52 on the rim of the stationary driven part, as appears in Figure 5, one of the overhanging extensions 71 of the driving part contacts the raised tail portion 4? of the holding latch as, as appears in Figure l, and pivots said latch to cause it to be released from the abutment l0. Immediately the stored up energy of the spring 73 rapidly orives or impulses the driven part ahead and, as this part is secured to the magneto shaft, necessarily the magneto sh aft and its armature are impulsed through the field of the magneto, thereby producing that necessary hot spark for ignition purposes in the engine. At this time the nib 2O prevents frictional contact of the entire surface of the back side of the latch with the extension '51, as can be seen.

Still looking at Figure 5,

the impulsed V travel of the driven part must be limited when the lower extension 52 thereof, as seen in the figure, strikes the lower end of the extension 78 on the buffer shell. This buffer extension 78 is, therefore, given such a blow that it causes the buffer shell to rotate slightly ahead, as permitted by the greater angular length of the slot 76 as compared with the angular length of the driver extension 60. The buf fer recoil, of course, is against the compression of the buffer spring which absorbs and minimizes the shock. As soon as the shock has been absorbed, the natural unwindi; action of the bufier spring returns the buffer shell to its normal, home driving seat against the driving extension ('30, as shown in Figure 2, and previously mentioned. In the meantime the opposite latch 46 catches the abutment 40, and the same operation is repeated. This continues intermittently then, as will be understood, until the engine speed gets up to such normal speed as permits efiicient spark generation in the magneto without the impulsing action. The centrifugal force developed by such rotative speed throws the latches, due to their heavy ends d8, outwardly and free of the abutment e0, so that the latches no longer can engage the abutment. The drive for the magneto is then directly through the driving spring 73, as will be understood. If excessive load slows down the rotative speed of the engine, then the impulse couplin automatically acts again as the force of gravity will then overcome the centrifugal force, causing the latches once again to engage the abutment 40. The impulse coupling of this invention is, therefore, of the full, automatic type.

From this detailed disclosure, it must now be obvious that an improved impulse coupling has been provided which achieves all of the desirable objects heretofore recited.

It is to be understood that it is intended to cover all such changes and modifications of the illustrative embodiment herein disclosed as do not materially depart from the spirit and scope of the invention, as is indicated in the following claims.

hat is claimed is:

1. In an impulse coupling, a driving member, a driven member connected to a magneto shaft, an intermediate member, a spring be tween the intermediate member and the driving member, and a spring between the driving member and the driven member.

2. In an impulse coupling, a driving mem ber, a driven member connected to a magneto shaft, an intermediate member, a spring having one end anchored to the intermediate member and its other end anchored to the driving member, and a second spring connected between the driving and driven members.

3. In an impulse coupling, a driving member, a driven member, an intermediate mem- M ber, a constantly tensioned buffer spring anchored between the driving and intermediate members, and a driving spring between the driving and driven members.

4. In an impulse coupling, a rotatable driving member, a rotatable driven member, an intermediate member having a slight rotative movement relative to the driving member, a tensioned butler spring anchored between the driving and intermediate members, and a driving spring between the driving and driven members.

5. In an impulse coupling, a driving member, a driven member, an intermediate member, a spiral buffer spring anchored between the driving and intermediate members, and a spiral driving spring between the driving and driven members.

6. In an impulse coupling, a driven member having a hub fast on a magneto shaft and extending therefrom, a driving member having a hub on the extended hub of the.

driven member, a buffer member movable with the driving member, a buffer spring secured at one end to the hub of the driving member and at its other end to the buffer member, and a driving spring secured at one end to the hub of the driving member and at its other end to the driven member.

7. In an impulse coupling, a driven ber having a hub fast on a magneto shaft nding therefrom, a. driving member ha ing ahub on the ext-ended hub of the driven member, a buffer men memspring anchored between the hub of the driving member and the butter member, and a driving spring connected between the drivand driven members.

8. In an impulse coupling, a driven member having a hub fast on magneto shaft and extending therefrom, a driving memberhaving a hub on the extended hub of the driven member, a buffer member movable with the driving member, a buter spring connected between the driving member and the buiier member, and a driving spring connected between the driving and driven members, each of said springs concentrically around the hub of the driving member.

9. In an impulse couplin, a driven menn ber having a hub fast on a ma "neto shaft and extending therefrom, a driving member having a hub on the extended hub of the driven member, buffer member movable with the driving member, a flat spiral bu or spring secured at one end to the hub of driving member and at its other end to the buffer member, a flat spiral driving spring secured at one end to the hub of the driving member and at its other end to the driven member, each of said springs arranged concentrically around the hub of the driving member, and a loose separator between said springs.

10. In an impulse coupling, a criving memarran d her movable with the driving member, a tensioned buffer member, a driven mom her, a buffer member having driving eoi ber, a bui'i' r member, means for driving the buiier from the driving member, a rimffor the builer, a spring encl se d by said rim and having connections with the driving member and louder, a driven member having a rim,- a spring enclosed by the rim and having connections witl the driving and dr' en members, and cooperating extensions between the buffer member and driven member.

12. In an impulse cou ng, a driving member having a hub, a buffer member, meal s for driving the butler member from the driving member, a rnn on the butfermember, atensioned buffer spring anchored to the hub of the driving member and to the rim of the buffer member, a driven member having a rim, a driving spring an hored to the hub of the driving member and to the rim of the driven member, and cooperating extensions between the butter member and driven member.

13. In an impulse coupling, a driving memher havin a hub, a buffer member, means for driving the bufier member from the driving member, a rim on the butter member, a tensioned bufier spring anchored to the hub of the drlvm 'rmember and to the rim of the i 2') buffer member, a driven member including a hub inside the hub of the driving member, a rim on the driven member, and a driving spring between the rim of the driven memher and the hub of the driving member, said buffer rim and driven member rim having cooperating builer extensions.

14. In an impulse coupling, a driving memher having a hub, a buiier member, means for driving the buffer member from the driving member, a rim on the butter member, a butter spring anchored to the rim of the buffer and to the hub of the driving member, a driven member having a hub inside the hub of the driving member, said driven member including a rim, a driving spring anchored to the rim of the driven member and to the hub of the driving member, and cooperation buffer extensions on the buffer rim and driven member rim.

15. In an impulse coupling, a driving memher having a hub, a butter member, means for driving the bufier member from the driving member, a spiral spring between the buffer member and hub of the driving member, said spring arranged concentrically around said hub,a driven member having a hub inside the hub of the driving member, a spiral spring between the driven member and the hub of the driving member, said nember, a but-Zer spring between the driving member, a driven mema driving spring betweeithe driving member and driven me u cer, and extensions ietween the buffer member and driven 11181117 ber,

I. In an impul e coupling, a hub having a reduced portion, a driving member on the reduced portion, a disk having a driving ex- =ension on reduced portion, means coking the member and disk on the reduced portion of the hub to form a unit therewith, a buffer member having a slot engageable by said extension to drive the buti'ermember, a butler spring between the hub and buffer nber, driven men-her, driving spring between the hub and he driven member, and extensions between the buiier member and the driven member. 7 I

18. in an impulse coupling, a driving memsuffer member driven directly thereby, biiiier spring between the driving member the buiier member, driven member, a spring between the criving and ven members, a stationary abutment adie driven member, a latch on the ember engageabie with the abutmenthe driven member against rotation member for disengaging the latch from the abutment to cause the driven member to be impulsed.

19. In an impulse coupling, a driving member, a butter member, means for drivin the buii er member with the driving member, a tensioned butler spring anchored at one end to the buffer member and at its other end to the driving member, a driven member, a driving spring between the driving and driven members, a stationary abutment adjacent the driven member, a latch pivotally carried on the driven member and engageable withthe abutment to lock the driven. member against rotation to wind the driving spring, and means on the driving member for disengaging the latch from the abutment to cause the driven member to be impulsed.

200 In an impulse coupling, a driving member having a hub, a butter member, means driving the buffer member with the drivmember, a buffer spring between the butter and the hub of the driving member, a driven member having a hub inside the hub of the driving member, a driving spring between the hub of the driving member and a driving extension included in said drivaged-by said extension to drive the butler i r men spiral be I w e1: rim and con-- t from d1 r n spring enclosed by the b nected between the b hub of driving having a hub hub or on member, a acted between the drii g her and enclosed by n iember, stationa ven member, in

nent to loci ons the rims or vcn. members,

In an impulse coupling, driving meme h. rim, a buffer member movable t riving member, a buffer spring between the bniier member and driving memher, a driven member, a spring between the driving and driven members, a stationary abutment adjacent the driven member, means on the driven member for engaging said abutment to lock the driven member against rotation, and extensions on the rim or the driving member for releasing the lock means.

23. In an impulse coupling, a driving memher having a rim, a buffer member movable with the drinng member, a buffer spring between the buffer member and driving memher, a driven member, a spring between the driving and driven members, a stationary abutn'ient acent the driven member, a latch pivotally carried on the driven member for engaging said abutment to lock the driven member against rotation, and an extension on the rim of the driving member overhangg the latch to engage a portion thereof to release the same from the abutment.

2a. In an impulse coupling, a driving memher having a rim, a buflfer member having a rim inside the rim of the driving member, means for driving the bulfer member from the driving member, a buffer spring connected between the driving member and the butfer member, a driven member having a rim inside the rim of the driving member, a drivin spring connected between the driving and driven members, cooperating extensions between the rims ot the buffer and driven members, latches on the driven member, a sta- 1 tionary abutment adjacent the driven memher With which the latches are adapted to engage one at time to lock the driven member against rotation, and extensions on the rim oi the drivin member acting one at a time to release the latches from the abutments.

25. In an impulse coupling, a driving memher having a hub and a rim, a butler member having a rim inside therim of the driving member, means for driving the buffer memher from the driving member, a spiral butler spring connected between the rim of the buffer member and the hub of the driving mem her, a driven member having a rim inside the rim of the driving member and tension cooperating with comple tensions on the rim of the bulier member, a spiral driving spring connected between the hub of the driving member and the rim of the driven member, a separator between the two springs, latches on the driven member, a stationary abutment adjacent the driven mem her with which the latches are adapted to enga 'e one a time to lock the driven member against rotation, and extensions on the rim of the driving member to engage a portion of the latches to release the same from the abutment, said extensions acting one at a time.

26. In an iapulse coupling, the combinaion of driving and driven members, a resildriving connection between said mement ers, and a flat, spiral, coil spring normally under stress to act a butter for the driven member when it is stopped after each impulse.

27. In an impulse coupling, a driving memher, a driven member connected to a magneto shaft, an intermediate member, a resilient shock absorbing means between the intermediate member and the driving member, and a spring driving connection between the driving and driven members.

28. In an impulse coupling, driving menber, a driven member, an intermediate member, a resilient cushion between the driving and intermediate members, and a spiral driving spring between the driving and driven members.

In testimony whereof I affix my signature.

LEOPOLD F. BURGER. 

